1. Field of the Invention
The invention relates to an electrical receptacle contact having at least one pair of contact spring arms with an outer back-up spring including an outer back-up spring.
2. Description of the Prior Art
An electrical contact of this type is known from German Patent Specification 32 48 078. Such electrical contacts usually are stamped in one piece from sheet metal and subjected to bending operations so as to form the pluggable contact. The contact spring arms thus consist of the same material and have the same thickness as the remaining portions of the contact. The spring force of the contact spring arms attainable in this manner often is not sufficient. This is why the desired spring force is generated with the aid of an outer back-up spring whose outer back-up spring arms press against the contact spring arms from the outside.
When the complementary contact inserted between the contact spring arms is a tab contact, the contact locations of the contact spring arms thus engage both sides of the tab contact with a contact force which does not only amount to the spring force of the contact spring arms, but to the sum of the spring forces of contact spring arms and outer back-up spring arms. Due to the fact that the type and thickness of the material for the outer back-up spring need not be selected depending on the material and the material thickness of the contact, such an outer back-up spring, in comparison with a contact having no such outer back-up spring, is capable of obtaining a considerable increase in the contact force that can be exerted by the contact spring arms on a tab contact inserted therebetween. Therefore, a high contact force and thus good and reliable electrical contacting can be achieved between contact and tab.
However, this advantage is obtained with the sacrifice that a correspondingly high mating force must be applied for mating receiving contact and tab contact. This becomes a problem in particular with multi-pole connectors having a multiplicity of such contacts. When such a multi-pole connector is mated with a complementary connector having a corresponding number of tab contacts, a mating force must be applied which instantly corresponds to the sum of the spring forces of all contact spring arms and of the spring forces of all outer-back up spring arms.